1. Field of the Invention
The present invention relates to a wireless communication system. More particularly, the present invention relates to a beamforming method and apparatus for acquiring transmission beam diversity in a wireless communication system.
2. Description of the Related Art
To meet the ever-increasing demand for wireless data traffic, wireless communication systems have evolved to support higher data rates. Recently commercialized 4th-Generation (4G) communication systems have been developed mainly toward spectral efficiency improvement to increase data rates. However, the explosively increasing wireless data traffic demand is difficult to meet merely with spectral efficiency improvement.
Accordingly, to meet the recent explosively-increasing wireless data traffic demand, research has been actively conducted on the use of broad frequency bands. At present, frequency bands used in mobile communication cellular systems are generally lower than 100 GHz, in which it is difficult to secure broadband frequencies. For this reason, a need exists to secure broadband frequencies in higher frequency bands. However, as the frequency band for wireless communication becomes higher, a propagation path loss increases, reducing a wave reaching distance and also a coverage.
To address these issues, beamforming has been on the rise as a key technique for alleviating a propagation path loss and increasing a wave reaching distance. The beamforming technique typically needs a beam selection technique for accurately measuring transmission and reception beams and for selecting and reporting the most proper beam at a base station and a terminal, respectively. However, an obstacle between the base station and the terminal or mobility of the terminal may cause a beam change which is difficult to catch up merely with the beam selection technique. Therefore, a need exists for a transmission method which is robust against a beam change.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.